Secondary battery pack of embedded type of novel structure

ABSTRACT

A secondary battery pack including a battery cell having first and second electrode terminals at a top thereof, an electrically insulative mounting member having an opening, through which the second terminal is exposed, the mounting member being mounted to a top of the cell, a protection circuit module (PCM) including a protection circuit board (PCB), having a protection circuit, loaded on the mounting member, a connection member (A) connected to the first terminal, and a connection member (B) connected to the second terminal, the PCB being provided with a through hole, through which the connection member (B) is exposed, and an insulative cap coupled to an upper end of the cell to surround the mounting member in which the connection members and the PCB are loaded on the mounting member, wherein the sum of a height of the PCM and a height of the cap is 3.0 mm or less.

TECHNICAL FIELD

The present invention relates to an embedded type secondary battery packhaving a novel structure, and, more particularly, to a secondary batterypack including a battery cell having first and second electrodeterminals formed at a top thereof, an electrically insulative mountingmember having an opening, through which the second electrode terminal ofthe battery cell is exposed, the electrically insulative mounting memberbeing mounted to a top of the battery cell, a protection circuit module(PCM) including a protection circuit board (PCB), having a protectioncircuit, loaded on the electrically insulative mounting member, aconnection member (A) connected to a first electrode terminal of thebattery cell, and a connection member (B) connected to the secondelectrode terminal of the battery cell via a safety element, the PCBbeing provided with a through hole, through which the connection member(B) is exposed, and an insulative cap coupled to an upper end of thebattery cell to surround the electrically insulative mounting member ina state in which the connection members and the protection circuit boardare loaded on the electrically insulative mounting member, wherein thesum of a height of the PCM and a height of the insulative cap is 3.0 mmor less.

BACKGROUND ART

As mobile devices have been increasingly developed, and the demand forsuch mobile devices has increased, the demand for secondary batterieshas also sharply increased. Among such secondary batteries is a lithiumsecondary battery exhibiting high energy density and operating voltageand excellent charge retention and service-life characteristics, whichhas been widely used as an energy source for various electronic productsas well as various kinds of mobile devices.

Depending upon kinds of external devices in which the lithium secondarybattery is used, the lithium secondary battery may be configured to havea detachable type structure in which the lithium secondary battery canbe easily inserted into and removed from the external devices or to havean embedded type structure in which the lithium secondary battery isembedded in the external devices. For example, the lithium secondarybattery can be inserted or removed into or from a device, such as amobile phone or a laptop computer, as needed. On the other hand, anotherdevice, such as an MPEG Audio Layer-3 (MP3) player, requires an embeddedtype battery pack due to the structure or capacity thereof

However, various kinds of combustible materials are contained in alithium secondary battery. As a result, the lithium secondary batterymay be heated or explode due to overcharge of the lithium secondarybattery, overcurrent in the lithium secondary battery, or other externalphysical impact applied to the lithium secondary battery. That is, thesafety of the lithium secondary battery is very low. Consequently,safety elements, such as a positive temperature coefficient (PTC)element and a protection circuit module (PCM), to effectively control anabnormal state of the lithium secondary battery, such as overcharge ofthe lithium secondary battery or overcurrent in the lithium secondarybattery, are loaded on a battery cell in a state in which the safetyelements are connected to the battery cell.

Generally, the PCM is electrically connected to the battery cell viaconductive nickel plates by welding or soldering. That is, nickel platesare connected to electrode tabs of the PCB by welding or soldering, andthe nickel plates are connected to electrode terminals of the batterycell by welding or soldering. In this way, the PCM is connected to thebattery cell to manufacture a battery pack.

It is required for the safety elements, including the PCM, to bemaintained in electrical connection with the electrode terminals of thebattery cell and, at the same time, to be electrically isolated fromother parts of the battery cell. To this end, a plurality of insulativemounting members or other parts is necessary, which complicates anassembly process of the battery pack. In particular, the sum of theheight of the PCM and the height of the insulative cap generally reaches3 mm with the result that a space necessary to receive the battery cellis reduced.

Meanwhile, insulative tapes are attached to respective members of thelithium secondary battery, including the PCM. In addition, a sealedportion of the battery case, in which the battery cell is mounted, ispartially bent, and an insulative tape is attached to it or a barcode isprinted on it. However, this process is very complicated.

Also, when external impact is applied to a battery pack, the PCM may bedamaged or dimensional stability of the battery pack may be greatlylowered due to the use of the insulative tapes, which exhibit lowmechanical strength.

Consequently, there is a high necessity for a technology that is capableof reducing the number of members mounted to the upper end of a batterycell to simplify an assembly process, reducing the number of weldingprocesses to reduce a defect rate, achieving stable coupling betweenmembers loaded on the upper end of the battery cell, and increasing thecapacity of the battery cell while solving the above-mentionedconventional problems.

DISCLOSURE Technical Problem

Therefore, the present invention has been made to solve the aboveproblems and other technical problems that have yet to be resolved.

Specifically, it is an object of the present invention to provide asecondary battery pack, the number of parts of which is reduced, theassembly process of which is simplified, and which has a batterycapacity greater than that of other battery packs having the samestandard.

It is another object of the present invention to provide a method ofmanufacturing a battery cell having a novel structure, durability ofwhich is improved against external impact such that the above secondarybattery pack can be manufactured.

Technical Solution

In accordance with one aspect of the present invention, the above andother objects can be accomplished by the provision of a secondarybattery pack including a battery cell having an electrode assembly of acathode/separator/anode structure disposed in a battery case togetherwith an electrolyte in a sealed state, the battery cell having first andsecond electrode terminals formed at a top thereof, an electricallyinsulative mounting member having an opening, through which the secondelectrode terminal of the battery cell is exposed, the electricallyinsulative mounting member being mounted to a top of the battery cell, aprotection circuit module (PCM) including a protection circuit board(PCB), having a protection circuit, loaded on the electricallyinsulative mounting member, a connection member (A) connected to a firstelectrode terminal of the battery cell, and a connection member (B)connected to the second electrode terminal of the battery cell via asafety element, the PCB being provided with a through hole, throughwhich the connection member (B) is exposed, and an insulative capcoupled to an upper end of the battery cell to surround the electricallyinsulative mounting member in a state in which the connection membersand the protection circuit board are loaded on the electricallyinsulative mounting member, wherein the sum of a height of the PCM and aheight of the insulative cap is 3.0 mm or less.

That is, in the secondary battery pack according to the presentinvention, the connection member (B), exposed through the through holeof the PCB, is electrically connected to the second electrode terminalof the battery cell via the PTC element from the above, and theconnection member (A) is electrically connected to the first electrodeterminal of the battery cell, in a state in which the PCM is loaded onthe electrically insulative mounting member. Consequently, electricalconnection is achieved using a simple connection method. Also, theassembly operation is easily performed, thereby greatly improvingmanufacturing efficiency.

Also, the connection member (A) extending from one end of the PCM is notbent, and the connection member (B) does not need an additional loadingspace. Consequently, it is possible to minimize a dead space, caused asthe connection members are bent for electrical connection of the safetyelement in the conventional art.

Particularly in the secondary battery pack according to the presentinvention, the thicknesses of the PCM and the insulative cap areminimized in order to minimize the sum of heights of the PCM and theinsulative cap, which are mounted to the upper end of the battery cell.For example, the insulative cap may have a thickness of 0.4 mm or less,and the PCB may have a thickness of 0.6 mm or less.

Since the thicknesses of the PCM and the insulative cap and the sum ofheights of the PCM and the insulative cap are greatly lower than thoseof the conventional secondary battery pack, and therefore, it ispossible to manufacture a secondary battery pack having higher energydensity than other secondary battery packs having the same standard.

The battery case requires easy machining and predetermined mechanicalstrength. For this reason, the battery case may be a prismatic metalcontainer. Preferably, the battery case is an aluminum container or astainless steel container.

In a preferred example, the second electrode terminal may be an anodeterminal, and the first electrode terminal may be a cathode terminal Forexample, a prismatic battery cell may be configured to have a structurein which an electrode terminal protruding from the top of the batterycell and a battery case of the battery cell form an anode terminal and acathode terminal, respectively, and an insulation member, such as agasket, is disposed between the anode terminal and the cathode terminalto insulate the anode terminal and the cathode terminal from each other.In the structure of the prismatic battery cell, therefore, the secondelectrode terminal may be an anode terminal protruding from the top ofthe battery case, and the first electrode terminal may be a cathodeterminal formed at the top of the battery case excluding the anodeterminal

Coupling (electrical connection) between the connection members and thePCM may be achieved using various methods. Preferably, the connectionmembers may be coupled to the bottom of the PCB using surface mounttechnology (SMT). The SMT prevents paste from remaining at the bottom ofthe PCB during soldering or the bottom of the PCB from being damage dueto heat during welding. Also, the SMT achieved accurate and reliablecoupling as compared with a conventional welding or soldering method.For reference, the SMT is widely used to mount surface mount type partson an electronic board, such as a printed circuit board (PCB).

In a preferred example, the connection member (B) may be coupled to thebottom of the through hole of the PCB. That is, the connection member(B) can be coupled to the safety element connected to the secondelectrode terminal through the through hole, thereby further simplifyingthe assembly process and minimizing the thickness of the PCM.

The safety element is an element, which is broken during conduction ofovercurrent or the resistance of which increases with the increase oftemperature. Preferably, the safety element is positive temperaturecoefficient (PTC) element. The connection member (B) coupled to the PTCelement serves to interrupt current at the upper end of the battery packwhen the temperature of the battery pack abruptly rises due to aninternal short circuit or the like. However, the safety element is notlimited to the PTC element. For example, a bimetal or a fuse may be usedas the safety element.

In the above structure, the PTC element may include a PTC body, a PCMcoupling part coupled to a top of the PTC body, and a battery cellcoupling part coupled to a bottom of the PTC body, and the PCM couplingpart may be coupled to the connection member (B) through the throughhole of the PCB.

Meanwhile, one end of the connection member (A) may be coupled to abottom of the PCB in a state in which the end of the connection member(A) extends longer than an outer circumference of the PCB such that theend of the connection member (A) is exposed upward. Preferably, theconnection member (A) has a thickness less than that of the electricallyinsulative mounting member. Consequently, it is possible to easilysecure a space necessary to locate the connection member (A) between oneend of the PCM and one end of the top of the battery cell.

In another preferred example, the secondary battery pack may furtherinclude an auxiliary mounting member having one end coupled to a bottomof the PCB and the other end coupled to the top of the battery cell isprovided such that the PCB is stably mounted to the battery cell.

Specifically, the auxiliary mounting member may be coupled to a positionopposite to the connection member (A), and the auxiliary mounting membermay be coupled to the bottom of the PCB in a state in which theauxiliary mounting member extends longer than the outer circumference ofthe PCB such that one end of the auxiliary mounting member is exposedupward. Consequently, the auxiliary mounting member is stably fixed tothe PCB while minimizing a dead space.

Also, the material for the auxiliary mounting member is not particularlyrestricted. Preferably, the auxiliary mounting member is formed of ametal plate, such as a nickel plate.

The coupling of the electrically insulative mounting member to the topof the battery case may be achieved, for example, by bonding, therebyachieving easiness in assembly process of the battery pack and securinga stable coupling state.

The insulative cap may have a predetermined height sufficient for atleast a portion of the insulative cap to surround the outercircumference of the upper end of the battery cell in a state in whichthe insulative cap is mounted to the battery cell. Preferably, theinsulative cap has a height of 0.4 mm or less, as previously described.Consequently, the height of the insulative cap is minimized as comparedwith the height of a conventional insulative cap, and therefore, it ispossible to manufacture a secondary battery pack having higher energydensity than other secondary battery packs having the same standard.

The secondary battery pack according to the present invention may bevariously applied irrespective of the kind or external shape of thebattery cell. Preferably, the secondary battery pack according to thepresent invention is applied to a battery pack including a prismaticsecondary battery as a battery cell.

The battery cell may be configured to have a structure in which anelectrode assembly is disposed in a battery case made of aluminum or analuminum alloy together with an electrolyte in a sealed state.

In accordance with another aspect of the present invention, there isprovided a method of manufacturing the battery cell with theabove-stated construction.

In a concrete example, the method includes (a) anodizing an entiresurface of a battery case in a state in which an uncoated margin sectionhaving a predetermined length is provided downward from an outercircumference of an upper end of the battery case and a connectionopening section, to which charge pins used to activate the battery cellare connected, is formed at a bottom of the battery case, (b) mountingan electrode assembly in the battery case and connecting a cap plate toan open upper end of the battery case by laser welding, (c) injecting anelectrolyte through an electrolyte injection port of the cap plate andactivating the battery cell, and (d) replenishing the electrolyte andsealing the electrolyte injection port.

In the method of manufacturing the battery cell according to the presentinvention, therefore, the uncoated margin section is provided at theupper end of the battery case and the connection opening section isprovided at the bottom of the battery case before the entire surface ofthe battery case is anodized. Consequently, it is possible to easilyconnect the cap plate to the open upper end of the battery case by laserwelding and to easily achieve connection between the electrode terminalsand the charge pins.

In a concrete example, the step (a) may include (a1) a defatting processof dipping the battery case in a defatting solution, drawing the batterycase from the defatting solution, and washing the battery case in water,(a2) an acid cleaning process of dipping the battery case in an acidcleaning solution, drawing the battery case from the acid cleaningsolution, and washing the battery case in water, and (a3) an anodizingprocess of anodizing the surface of the battery case.

That is, durability and corrosion resistance of the battery case areimproved through anodizing of the battery case. Also, dyeing of thebattery case is possible due to small porosity and fiber propertythereof, thereby improving wear resistance and utility of the batterycase.

The uncoated margin section may extend downward from the outercircumference of the upper end of the battery case by a length of 0.5 to5 mm. If the length of the uncoated margin section is too long, it maybe difficult to achieve desired durability of the battery case based onsurface treatment, which is not preferable. On the other hand, if thelength of the uncoated margin section is too short, it may not bepossible to easily carry out laser welding, which is not preferable.

The method of forming the uncoated margin section is not particularlyrestricted. For example, the uncoated margin section may be formed byanodizing the battery case in a state in which an insulation material isapplied to the battery case or an insulator or an insulation tape ismounted or attached to the battery case and removing the insulationmaterial, the insulator, or the insulation tape.

The laser welding of the step (b) may be changed according to processconditions. Preferably, the laser welding of the step (b) is carried outalong the outer circumference of the battery cell above the cap plate.

In a preferred example, the step (a) may include forming a connectionopening section, to which the charge pins used to activate the batterycell at the step (c) are connected, at the bottom of the battery case.That is, the connection opening section is formed at the bottom of thebattery case contacting the charge pins, particularly the cathode pinexhibiting cathode polarity, thereby performing effective charge basedon stable contact.

Also, the shape of the connection opening section is not particularlyrestricted so long as the connection opening section corresponds to thecharge pins. For example, the connection opening section may be formedin a circular, oval, or polygonal shape in plan.

The method of forming the connection opening section is not particularlyrestricted. For example, the connection opening section may be formed byanodizing the battery case in a state in which an insulation material isapplied to a portion of the bottom of the battery case or an insulatoror an insulation tape is mounted or attached to a portion of the bottomof the battery case and removing the insulation material, the insulator,or the insulation tape.

Meanwhile, the method may further include sealing the connection openingsection using an insulation member after the step (d), therebyprotecting the battery cell and maintaining electrical insulation of thebattery cell.

The material for the insulation member is not particularly restricted solong as the insulation member protects the connection opening sectionfrom the outside and maintains electrical insulation of the connectionopening section. Preferably, the insulation member is at least oneselected from a group consisting of an insulation tape, glue, andcoating.

Effects of the Invention

As is apparent from the above description, in a secondary battery packaccording to the present invention, the sum of the height of a PCM andthe height of an insulative cap is minimized, and therefore, it ispossible to increase battery capacity of the secondary battery pack ascompared with other battery packs having the same standard.

Also, the entire surface of a battery case is anodized in a state inwhich an uncoated margin section is provided at the upper end of thebattery case and a connection opening section is provided at the bottomof the battery case, thereby improving durability of the secondarybattery pack and easily performing laser welding of a cap assembly andconnection of charge pins.

DESCRIPTION OF DRAWINGS

The above and other objects, features and other advantages of thepresent invention will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is an exploded perspective view showing the upper end of abattery cell according to an embodiment of the present invention and aninsulative cap, on which an insulative mounting member is loaded;

FIG. 2 is a partially enlarged side view of FIG. 1;

FIG. 3 is a partial perspective view showing a state in which theinsulative mounting member is mounted to the upper end of the batterycell;

FIG. 4 is a partial perspective view showing a state in which aprotection circuit module (PCM) is mounted at the structure of FIG. 2;

FIG. 5 is a partial perspective view showing a state in which theinsulative cap is mounted at the structure of FIG. 4;

FIG. 6 is a partial perspective view showing the upper end of a batterycell according to another embodiment of the present invention;

FIG. 7 is a partial side view of FIG. 6;

FIG. 8 is a front view showing the battery cell to which connectionpins, which are used during a charging process to activate the batterycell, are coupled;

FIG. 9 is an exploded perspective view showing the battery cell, ananodized part, and an insulation tape; and

FIG. 10 is a partial perspective view showing the lower end of thebattery cell.

DETAILED DESCRIPTION OF THE INVENTION

Now, preferred embodiments of the present invention will be described indetail with reference to the accompanying drawings. It should be noted,however, that the scope of the present invention is not limited by theillustrated embodiments.

FIG. 1 is an exploded perspective view showing the upper end of abattery cell according to an embodiment of the present invention and aninsulative cap, on which an insulative mounting member is loaded, FIG. 2is a partially enlarged side view of FIG. 1, FIG. 3 is a partialperspective view showing a state in which the insulative mounting memberis mounted to the upper end of the battery cell, FIG. 4 is a partialperspective view showing a state in which a protection circuit module(PCM) is mounted at the structure of FIG. 2, and FIG. 5 is a partialperspective view showing a state in which the insulative cap is mountedat the structure of FIG. 4.

Referring to these drawings, a secondary battery pack 100 is configuredto have a structure including a battery cell 110, an electricallyinsulative mounting member 120 mounted to the top of the battery cell110, a protection circuit module (PCM) 130, and an insulative cap 140mounted to the upper end of the battery cell 110 while surrounding theinsulative mounting member 120.

The battery cell 110 is configured to have a structure in which anelectrode assembly of a cathode/separator/anode structure is mounted ina battery case 150 made of aluminum together with an electrolyte in asealed state, an anode terminal 111 protrudes from the middle of the topof the battery cell 110, and a cathode terminal 112 is formed at the topof the battery cell 110 excluding the anode terminal 111.

The electrically insulative mounting member 120 is provided with anopening 121, through which the anode terminal 111 of the battery cell110 is exposed.

The PCM 130 includes a protection circuit board (PCB) 133 loaded on theinsulative mounting member 120, the PCB 133 having a protection circuit,a connection member 132 connected to the cathode terminal 112, and aconnection member 136 connected to the anode terminal 111 via a positivetemperature coefficient (PTC) element 134. The PCB 133 is provided witha through hole 137, through which the connection member 136 is exposed.

The connection member 136 is coupled to the bottom of the through hole137 of the PCB 133.

Referring to FIG. 2, the PTC element 134 includes a PTC body 1341, a PCMcoupling part 1342 coupled to the top of the PTC body 1341, and abattery cell coupling part 1343 coupled to the bottom of the PTC body1341. The PCM coupling part 1342 is coupled to the connection member 136through the through hole 137.

Meanwhile, one end of the connection member 132 is coupled to the bottomof the PCB 133 by surface mount technology (SMT) in a state in which theend of the connection member 132 extends longer than the outercircumference of the PCB 133 such that the end of the connection member132 is exposed upward.

An auxiliary mounting member 135, formed of a nickel plate, having oneend coupled to the bottom of the PCB 133 and the other end coupled tothe top of the battery cell 110 is provided such that the PCB 133 can bestably mounted to the battery cell 110. The auxiliary mounting member135 is coupled to a position opposite to the connection member 132.

The insulative cap 140 is made of an electrically insulation material.The electrically insulative cap 140 is formed to surround the insulativemounting member 120 in a state in which the connection members 132 and136 and the protection circuit board 133 are loaded on the electricallyinsulative cap 140.

Also, referring to FIGS. 4 and 5, the insulative cap 140 is coupled tothe top of the battery case by bonding. The insulative cap 140 has athickness w of about 0.3 to 0.4 mm, and the PCB 133 has a thickness W ofabout 0.4 to 0.6 mm. As a result, the sum H of a height of the PCM 130and a height of the insulative cap 140 is 3.0 mm or less.

In the secondary battery pack 100 according to the present invention,therefore, the connection member 136, exposed through the through hole137 of the PCB 133, is electrically connected to the anode terminal 111of the battery cell 110 via the PTC element 134 from the above, and theconnection member 132 is electrically connected to the cathode terminal112 of the battery cell 110, in a state in which the PCM 130 is loadedon the insulative mounting member 120. Consequently, electricalconnection is achieved using a simple connection method. Also, the sumof the height of the PCM 130 and the height of the insulative cap 140 is3 mm or less. Consequently, it is possible to manufacture a secondarybattery pack having higher energy density than other secondary batterypacks having the same standard.

FIG. 6 is a partial perspective view showing the upper end of a batterycell according to another embodiment of the present invention, FIG. 7 isa partially enlarged side view of FIG. 6, and FIG. 8 is a front viewshowing the battery cell to which connection pins, which are used duringa charging process to activate the battery cell, are coupled.

Referring to these drawings, a battery cell 110 having an electrodeassembly disposed in a battery case 150 made of aluminum in a sealedstate is manufactured as follows. First, the entire surface of thebattery case 150 is anodized (155) (see FIG. 9) in a state in which anuncoated margin section 151 having a length h of about 3 mm is provideddownward from the outer circumference of the upper end of the batterycase 150 and a connection opening section 162, to which charge pins 160and 161 used to activate the battery cell 110 are connected, is formedat the bottom 159 of the battery case 150.

Subsequently, the electrode assembly is mounted in the battery case 150,a cap plate 152 is connected to the open upper end of the battery case150 by laser welding, an electrolyte is injected through an electrolyteinjection port 153 of the cap plate 152, and the battery cell isactivated. Subsequently, the electrolyte is replenished, and then theelectrolyte injection port 153 is sealed.

At this time, the uncoated margin section 151 is formed by anodizing thebattery case 150 in a state in which an insulation material (not shown)is applied to the battery case 150 and removing the insulation material.

Also, the laser welding is carried out along the outer circumference ofthe battery cell 110 above the cap plate 152 (see an arrow shown in FIG.6), and therefore, it is possible to easily perform the laser welding ofthe cap assembly.

FIG. 9 is an exploded perspective view showing the battery cell, ananodized part, and an insulation tape, and FIG. 10 is a partialperspective view showing the lower end of the battery cell.

Referring to these drawings together with FIGS. 6 to 8, the connectionopening section 162 is formed in a quadrangular shape in plan.Alternatively, the connection opening section 162 may be formed invarious shapes in plan.

Also, the connection opening section 162 is formed by anodizing (155)the battery case 150 in a state in which an insulation material (notshown) is applied to a portion of the bottom of the battery case 150 andremoving the insulation material.

After the step of replenishing the electrolyte and sealing theelectrolyte injection port, the connection opening section 162 is sealedusing an insulation tape 165.

Consequently, it is possible to easily achieve the connection of thecharge pins by the provision of the connection opening section 162.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. A secondary battery pack comprising: a battery cell having anelectrode assembly of a cathode/separator/anode structure disposed in abattery case together with an electrolyte in a sealed state, the batterycell having first and second electrode terminals formed at a topthereof; an electrically insulative mounting member having an opening,through which the second electrode terminal of the battery cell isexposed, the electrically insulative mounting member being mounted to atop of the battery cell; a protection circuit module (PCM) comprising aprotection circuit board (PCB), having a protection circuit, loaded onthe electrically insulative mounting member, a connection member (A)connected to a first electrode terminal of the battery cell, and aconnection member (B) connected to the second electrode terminal of thebattery cell via a safety element, the PCB being provided with a throughhole, through which the connection member (B) is exposed; and aninsulative cap coupled to an upper end of the battery cell to surroundthe electrically insulative mounting member in a state in which theconnection members and the protection circuit board are loaded on theelectrically insulative mounting member, wherein a sum of a height ofthe PCM and a height of the insulative cap is 3.0 mm or less.
 2. Thesecondary battery pack according to claim 1, wherein the insulative caphas a thickness of 0.4 mm or less.
 3. The secondary battery packaccording to claim 1, wherein the PCB has a thickness of 0.6 mm or less.4. The secondary battery pack according to claim 1, wherein the batterycase is a prismatic metal container.
 5. The secondary battery packaccording to claim 1, wherein the second electrode terminal is an anodeterminal protruding from a middle of the top of the battery cell, andthe first electrode terminal is a cathode terminal formed at the top ofthe battery cell excluding the anode terminal.
 6. The secondary batterypack according to claim 1, wherein the connection members are coupled toa bottom of the PCB using surface mount technology (SMT).
 7. Thesecondary battery pack according to claim 1, wherein the connectionmember (B) is coupled to a bottom of the through hole of the PCB.
 8. Thesecondary battery pack according to claim 1, wherein the safety elementis a positive temperature coefficient (PTC) element.
 9. The secondarybattery pack according to claim 8, wherein the PTC element comprises aPTC body, a PCM coupling part coupled to a top of the PTC body, and abattery cell coupling part coupled to a bottom of the PTC body, the PCMcoupling part being coupled to the connection member (B) through thethrough hole of the PCB.
 10. The secondary battery pack according toclaim 1, wherein one end of the connection member (A) is coupled to abottom of the PCB in a state in which the end of the connection member(A) extends longer than an outer circumference of the PCB such that theend of the connection member (A) is exposed upward.
 11. The secondarybattery pack according to claim 1, further comprising an auxiliarymounting member having one end coupled to a bottom of the PCB and theother end coupled to the top of the battery cell such that the PCB isstably mounted to the battery cell.
 12. The secondary battery packaccording to claim 11, wherein the auxiliary mounting member is coupledto a position opposite to the connection member (A).
 13. The secondarybattery pack according to claim 12, wherein the auxiliary mountingmember is coupled to the bottom of the PCB in a state in which theauxiliary mounting member extends longer than an outer circumference ofthe PCB such that one end of the auxiliary mounting member is exposedupward.
 14. The secondary battery pack according to claim 11, whereinthe auxiliary mounting member is a nickel plate.
 15. The secondarybattery pack according to claim 1, wherein the insulative cap is coupledto a top of the battery case by bonding.
 16. The secondary battery packaccording to claim 1, wherein the battery cell is a lithium secondarybattery cell.
 17. The secondary battery pack according to claim 1,wherein the battery cell has an electrode assembly disposed in a batterycase made of aluminum or an aluminum alloy together with an electrolytein a sealed state.
 18. A method of manufacturing a battery cellaccording to claim 17, the method comprising: (a) anodizing an entiresurface of a battery case in a state in which an uncoated margin sectionhaving a predetermined length is provided downward from an outercircumference of an upper end of the battery case and a connectionopening section, to which charge pins used to activate the battery cellare connected, is formed at a bottom of the battery case; (b) mountingan electrode assembly in the battery case and connecting a cap plate toan open upper end of the battery case by laser welding; (c) injecting anelectrolyte through an electrolyte injection port of the cap plate andactivating the battery cell; and (d) replenishing the electrolyte andsealing the electrolyte injection port.
 19. The method according toclaim 18, wherein the step (a) comprises: (a1) a defatting process ofdipping the battery case in a defatting solution, drawing the batterycase from the defatting solution, and washing the battery case in water;(a2) an acid cleaning process of dipping the battery case in an acidcleaning solution, drawing the battery case from the acid cleaningsolution, and washing the battery case in water; and (a3) an anodizingprocess of anodizing the surface of the battery case.
 20. The methodaccording to claim 18, wherein the uncoated margin section extendsdownward from the outer circumference of the upper end of the batterycase by a length of 0.5 to 5 mm.
 21. The method according to claim 18,wherein the uncoated margin section is formed by anodizing the batterycase in a state in which an insulation material is applied to thebattery case or an insulator or an insulation tape is mounted orattached to the battery case and removing the insulation material, theinsulator, or the insulation tape.
 22. The method according to claim 18,wherein the laser welding of the step (b) is carried out along an outercircumference of the battery cell above the cap plate.
 23. The methodaccording to claim 18, wherein the step (a) comprises forming theconnection opening section, to which the charge pins used to activatethe battery cell at the step (c) are connected, at the bottom of thebattery case.
 24. The method according to claim 23, wherein theconnection opening section is formed in a circular or polygonal shape inplan.
 25. The method according to claim 23, wherein the connectionopening section is formed by anodizing the battery case in a state inwhich an insulation material is applied to a portion of the bottom ofthe battery case or an insulator or an insulation tape is mounted orattached to a portion of the bottom of the battery case and removing theinsulation material, the insulator, or the insulation tape.
 26. Themethod according to claim 23, further comprising sealing the connectionopening section using an insulation member after the step (d).
 27. Themethod according to claim 26, wherein the insulation member is at leastone selected from a group consisting of an insulation tape, glue, andcoating.